Field of the Invention
The present invention pertains generally to nuclear power plants and more specifically to an offshore, floating, moored, nuclear power generating plant, integrated into the submerged hull of a spar or cell spar platform. More specifically, the present invention relates to an offshore nuclear power plant comprised of a multiplicity of individual spar cells each containing a reactor vessel.
Description of the Prior Art
There exists unequivocal evidence that man made contributions to global warming through increased emissions of heat and greenhouse gases from various forms of carbon fuel combustion, can and must be eliminated to allow our ecosystem to sustainably continue to provide a habitable environment. This fact, combined with rapidly diminishing hydrocarbon reserves (i.e. coal and natural gas) and constantly escalating fuel costs, has ignited a growing global effort to shift to a sustainable, renewable energy powered future. Presently, there is a global consensus among energy experts that, in order to make the required leap from the current unsustainable energy status quo, a new generating technology is required to provide a bridge to sustainable, all renewable energy powered future.
Nuclear energy has traditionally shown the most promise for affordable, clean, reliable power. All commercial nuclear power plants in the United States are currently sighted on land, most on residentially valuable coastal, river or lake shores for access to cooling water. Sighting nuclear power plants on coastal locations results in the installations being vulnerable to seismic events, cyclones and tsunami, thereby escalating the costs of construction and safe operation. The majority of said power plants are also surrounded by high density population centers escalating land and water prices and face growing public resistance to land based nuclear power. These issues have traditionally been the impetus to design sustainable, affordable offshore nuclear power plant.
The principle public, regulatory, and industry concerns regarding land based nuclear power plants include: protection from operational nuclear accidents; protection from nuclear accidents generated by natural calamities; protection from terrorist attacks on nuclear power plants in populated areas; environmental contamination protection from nuclear power plant operations; competition with population needs for water resources; large high value land requirements; expensive, lengthy construction and commissioning times, escalating ratepayer costs; nuclear fuel consumption and resultant waste proliferation; stolen nuclear fuel facilitating illicit nuclear weapons proliferation; and safety and reliability of existing nuclear plants operating past original license term.
In addition to the above concerns, power generating industry must constantly balance the electrical supply to randomly fluctuating demand, often requiring rapid adjustments to meet unpredictable occurrences affecting the grid. In the aftermath of the Fukushima, Japan disaster on Mar. 11, 2011, the public has increased their volume of dissent. Government regulatory agencies and power plant owners are attempting to address these issues for land based nuclear facilities, but the public is justifiably wary. Japan has currently shut down all nuclear power plants for maintenance and upgrading, and have used the 2012 peak summer season demand to evaluate permanent abandonment of nuclear power for electricity generation. The United States is concurrently promoting and subsidizing the design and implementation of next generation land based reactors, emphasizing small, modular designs to address these concerns. It should be further noted that oceans cover most of the earth's surface and land is comparatively a much more scarce resource.
The prior art offshore nuclear power plants fall into three categories: fixed, floating and submersible. Of the floating concepts and patents, the first was the Sturgis (˜1960′s), a retired U.S. Navy vessel that was gutted and fitted with an MH1, nuclear generating plant. It provided power for the U.S. Army installation at Lake Gatun, Panama; and although successful, it did not generate commercial interest, and was retired.
In May 2012, World Nuclear News reported that Russia is building a fleet of floating nuclear power plants, which employ their icebreaker nuclear power plants, to be deployed to support mining and hydrocarbon processing in the artic. Resembling cruise ships, the vessels are vunerable in adverse weather and turbulent sea surface conditions.
In another example, U.S. Pat. No. 3,837,308 describes an offshore floating power plant comprised of a double walled spherical shell containing a nuclear reactor powering multiple generators, to produce and export electricity. This plant floats on the surface, anchored to the sea floor and incorporates a unique counter-balance mechanism to mitigate the wave motion on the plant. This costly unproven, complex design was never constructed.
U.S. Pat. No. 3,962,877 describes a fixed offshore power plant encompassing gas or petroleum fired turbines and steam generators encased in the support structure. The support structure extends legs to the seafloor positioning all equipment above the surface of the sea. This design fails to address vulnerabilities to cyclones, tsunami, seismic events, and carbon emission proliferation.
U.S. Pat. No. 4,302,291 describes an underwater nuclear power generating plant comprising a triangular platform formed by tubular legs supporting large spherical pressure vessels and smaller cylindrical auxiliary pressure vessels. The system requires the operators to remain submerged for extended periods and crew and materials transfer would be by submarine rendering it financially unattractive and logistically impractical.
U.S. Pat. No. 4,919,882 describes a modularized nuclear steam supply system installed on a barge and floated to its coffer dam site, which is representative of a plurality of surface floating power plant designs, each having the same advantages in construction cost and time saving, yet however, sharing the same catastrophic disadvantages to include seismic, tsunami, and cyclone vulnerabilities, or the threat of terrorist attack, as well as nuclear environmental impacts, and resource competition with the public.
Yet further in the prior art, U.S. Pub. Pat. App. No. 2009/0256421 describes a nuclear steam system similar to U.S. Pat. No. 4,919,882 above, except that it is self propelled. However, this proposal fails for the same reasons.
U.S. Pat. No. 5,247,553 describes an unmanned “submerged passively safe power station” capable of generating at least 600 MWe utilizing a pressurized water reactor. These power stations are submarine drones which are completely self-contained and operated remotely. The stations are guided into position and tethered above the seafloor. The invention was intended to provide temporary power to aid developing countries with little or no infrastructure and for use in an emergency response to a catastrophe where the usual power plant facilities have sustained damage. This technology has some safety limitations, would be prohibitively expensive, and to date has not been built.
U.S. Pub. Pat. App. No. 2011/0158370 describes an offshore, floating, moored nuclear powered energy carrier plant. This invention proposes using a naval nuclear reactor generator to provide power to hydrocarbon refinement process equipment installed on a standard semi-submersible offshore oil rig. The inventor further specifies that the plant does not export power to the commercial electrical grid, and is inoperable in stormy ocean conditions.
U.S. Pat. No. 7,978,806 describes an un-manned seafloor power station. The reactor generator units are installed in a geodesic sphere which floats submerged, and is tethered with cables to a gravity mat located on the ocean floor. The sphere is raised and lowered by winches for maintenance and refueling. All of the operations of the station are controlled remotely from an onshore base. The invention fails address nuclear fuel consumption and waste proliferation, and cost effectiveness.
Accordingly, mindful of the failings of the prior art, and the immediacy of the need to develop an affordable, sustainable, carbon free means of power generation, a first object of the present invention is to provide an offshore, semi-submersible, floating, moored, modular, nuclear power plant and multipurpose platform.
A second object of the present invention is to provide a method of construction which maximizes the time and cost savings by employing standardized, modularized assembly of the constituent parts on parallel construction pathways, that is achieved by simply employing an existing oil rig and reactor generation module construction methods and manufacturers, who have reduced the construction time of comparably sized oil rigs and navy nuclear modules to less than three years.
A third object of the present invention is to provide said power plant in a manner that minimizes or eliminates the threat of contamination or injury to the general public from operational accidents accomplished by locating the power plant offshore, away from any population, employing naval reactors which have a perfect safety history. Also, locating the power plant in cold water shall prevent any catastrophic melt downs.
A fourth object of the present invention is to protect the public and the power plant from damage and contamination from effects of natural calamities, specifically seismic events, tsunami, and cyclones, that is accomplished by employing the spar or cell spar platform design, proven to insulate the platform from seismic events, tsunami, and cyclones when the present invention is deployed offshore, permitting safe, uninterrupted operations.
A fifth object of present invention is to protect the public and power plant from damage and contamination resulting from a successful terrorist attack, again achieved by deploying offshore and having a “fail safe” capability, which diminishes its target value and provides a clear line of sight of any potential surface terrorist threat. In addition to the safety of isolation, the platform employs the latest navel threat detection technology to prevent a stealth terrorist attack, and can ascend, submerge, and maneuver to inhibit boarding.
A sixth object of the present invention is to prevent any environmental degradation or contamination resulting from power plant operations or location, that is achieved by maintaining a closed loop cooling water system, isolating any radioactive water from contact with seawater. Further, the seawater used in the cooling cycle is returned to the environment at a closely matching ambient seawater temperature. Additionally, to avoid environmental contamination the submerged hull will not be applied with environmentally deleterious antifouling coatings and will be maintained using small submersibles.
A seventh object of the present invention is to eliminate competition with the public for scarce natural resources, specifically potable water and land, that is again, achieved by locating the power plant offshore, minimizing land needs and immersing the power plant in unlimited cooling water, eliminating any competition with the public for said resources.
An eighth object of the present invention is to minimize consumption of nuclear fuel and contributions to nuclear waste repositories, while preventing terrorist acquisition of nuclear material, that is achieved through use of naval nuclear reactors, which require onsite fuel rod exchange only after 20 to 50 years, model dependent, greatly reducing nuclear waste contributions and eliminating the need to maintain an onsite nuclear waste storage facility, removing the attraction to terrorists to steal fuel.
A ninth object of the present invention is to provide a means to efficiently balance the fluctuations in electrical supply/demand, which is achieved by utilizing multiple modular naval nuclear reactors, which are designed for rapid adjustments. Additionally, by deploying a fleet of the present invention, a stable but highly adjustable baseline supply network would by created, capable of mitigating disruptive fluctuations in power supply and demand quickly and efficiently, complementing less predictable and responsive renewable power source such as wind and solar.
A tenth object of the present invention is to avoid the vulnerability of all single reactor nuclear power plant designs to relatively minor component and material failures causing service interruptions; and provide a power plant minimally affected by said failures or required maintenance, that is achieved by utilizing multiple, compact, modular, naval nuclear reactor-generators, that are interconnected through standard steam piping design, facilitating isolation of any failed component(s), allowing all unaffected reactor-generators continued operation, adjusting to mitigate the reduced power contribution, and facilitating repairs without service interruption.
An eleventh object of the present invention is to provide a means to supply ancillary cogeneration services such as; desalinated potable water, hydrogen extraction, and HVAC steam and cooling water for shore based demands, that is achieved by integrating the power generating decks into the submerged hull of the platform, freeing the topside structure to house the required cogeneration equipment, and by diverting steam and electricity from the reactor-generators to the cogeneration equipment as required.
A twelfth object of the present invention is to produce a sustainable, alternative power generation technology that is economically competitive with unsubsidized carbon emitting power generation, including natural gas, thereby providing a means to create a “bridge” to sustainable, all renewable energy generation, that is achieved by the deployment of a fleet of the present invention, which have overnight construction costs and operating expenses, including decommissioning, lower than natural gas fired power plants not including gas fuel costs, providing clear economic incentive to phase out all carbon emitting power plants, as well as existing, aging land based nuclear power plants.
To achieve the foregoing and other objects, and in accordance with the purpose of the present invention as embodied and broadly described herein.